כִּֽי־תִהְיֶ֨יןָ לְאִ֜ישׁ שְׁתֵּ֣י נָשִׁ֗ים הָאַחַ֤ת אֲהוּבָה֙ וְהָאַחַ֣ת שְׂנוּאָ֔ה וְיָֽלְדוּ־ל֣וֹ בָנִ֔ים הָאֲהוּבָ֖ה וְהַשְּׂנוּאָ֑ה וְהָיָ֛ה הַבֵּ֥ן הַבְּכ֖וֹר לַשְּׂנִיאָֽה׃
If a man have two wives, the one beloved, and the other hated, and they have borne him children, both the beloved and the hated; and if the first-born son be hers that was hated;
The Five Books of Moses, by Everett Fox
A tension that is played out in the Jacob and Joseph stories in Genesis, the conflict between two wives and their sons must have been a troubling reality in the polygamous ancient Near East. This could be conventionally solved by a father’s selection of the “firstborn,” but note the brake put on the father’s absolute control (Frymer-Kensky 1992a).